Aircraft and other aerospace vehicles utilize a number of control surfaces, such as wing flaps, to achieve their aerodynamic performance. These surfaces are typically moveable by the pilot, and their proper use requires the pilot to have accurate information concerning the surface's actual position relative to the vehicle. Prior art position transmitters used in the aerospace field utilize a combination of mechanical and electronic components sealed within a suitable enclosure to determine the position of the control surface and to provide information to the pilot or the vehicle control systems concerning such position.
As is well known, aerospace vehicles operate in a variety of precipitation, humidity, and altitude conditions. Precipitation and humidity often lead to corrosion, and therefore, prior art position transmitters have tried to seal their mechanical and electronic components inside a hermetic enclosure to prevent such damage. However, the hermetic seals in prior art devices have been observed to fail, and when they do, humid air that passes into the enclosure condenses, causes corrosion damage, and renders the position transmitter inaccurate and eventually unusable. Even minor breaks in the hermetic seal cause problems, especially when the transmitter and the aircraft it is attached to cycles between high and low altitudes characterized by low and high humidity levels, respectively.
Because proper functioning of the position transmitter is crucial for safe operation of the flight vehicle, there has been a longstanding need within the aerospace industry for a enclosure with improved resistance to damage caused by the effects of moist air. The present invention satisfies that need.